tbuckley/cabot-search huggingface dataset:
BIOM-41. IDENTIFICATION OF GLIOMA CELLS BY PROFILING SINGLE-CELL BIOPHYSICAL PROPERTIES THROUGH MULTICONSTRICTION MICROFLUIDIC CHANNELS
Authors: Xiang Ren, Hongming Ji, Xin Geng
Journal: Neuro-Oncology (2022)

Abstract This study introduces a multicontraction microfluidic channel that can differentiate glioma cells from normal glio cells. As cells pass through successive constriction channels, the incremental velocity and varying size profiles of the cells will be collected, reflecting their biophysical properties. The data of high-dimensional variables were analyzed , including the cell sizes, velocities, and velocity increments. The prediction value is used to represent the difference between two groups using the established classification model from high-dimensional variables. At the same time, we prepared three groups of primary tumor cells from patients with different grades of glioma to verify the efficacy of this classification method. The results show that in this microfluidic channel, the diagnostic model made of cell biophysical properties can well identify glioma cells, which gives a novel method for efficient identification of circulating tumor cells and rapid pathological diagnosis.
IMMU-38. MYC DRIVEN IMMUNE SUPPRESSION IN GROUP 3 MEDULLOBLASTOMA
Authors: Siddhartha Mitra, Daniel Picard, Nan Qin, Allison Cole, Joselyn Cruz Cruz, Viktoria Marquardt, Sujatha Venkataraman, Rajeev Vibhakar, Marc Remke
Journal: Neuro-Oncology (2022)

Abstract BACKGROUND The expression of MYC in tumor cells regulates the tumor microenvironment through innate and adaptive immune effector cells and immune regulatory cytokines. MYC has also been shown to regulate the expression of the immune checkpoint gene products CD47 and programmed death-ligand 1 (PD-L1). While PD-L1 inhibits adaptive immune response, CD47 on tumor cells binds to SIRPa on macrophages and acts as a “Don’t eat me” signal. We have previously shown that blocking the CD47-SIRPa pathway significantly decreases tumor burden and increases survival in five etiologically distinct adult and pediatric brain tumor xenograft models, including Group 3 or MYC-driven MB, by activating macrophage-mediated phagocytosis. METHODS We performed a primary screen including 78 epigenetic inhibitors and a secondary screen including 20 histone deacetylase inhibitors (HDACi) to compare response profiles in ATRT, medulloblastoma (n = 14), and glioblastoma (n = 14). This unbiased approach revealed the preferential activity of Class I HDACi in MYC-driven medulloblastoma mediated by induction of apoptosis, reduction in MYC transcription, and release of pro-inflammatory cytokines in MYC-driven medulloblastoma, with little to no activity in non-MYC-driven medulloblastoma, AT/RT, and glioblastoma in vitro. In addition, we tested the combinatorial effect of directly targeting the MYC/MAX interaction using MYCI-975 and the CD47-SIRPa phagocytosis checkpoint pathway using in-vitro phagocytosis assays and in-vivo xenograft models. In two orthotopic mouse models of MYC-driven medulloblastoma, MYCi975 displayed anti-tumoral effects at the primary site and the metastatic compartment. Furthermore, RNA sequencing revealed NFκB pathway induction as a response to MYC treatment, followed by interferon-gamma (IFN-G) release and cell surface expression of engulfment (“eat-me”) signals (such as calreticulin) and enhanced in vitro phagocytosis and survival in tumor-bearing mice. CONCLUSION Together, these findings suggest a dynamic relationship between MYC amplification and innate immune suppression in MYC-medulloblastoma and support further investigation of phagocytosis modulation as a strategy to enhance cancer immunotherapy responses.
IMMU-06. REDUCTION OF CD4+ T CELLS NEGATIVELY AFFECTS SURVIVAL IN OLD BUT NOT YOUNG MICE WITH GLIOBLASTOMA
Authors: Lijie Zhai, April Bell, Kristen Lauing, Prashant Bommi, Erik Ladomersky, Xinlei Mi, Masha Kocherginski, James Chandler, Craig Horbinski, Amy Heimberger, Rimas Lukas, Derek Wainwright
Journal: Neuro-Oncology (2022)

Abstract OBJECTIVE Previous work indicates poorer survival outcomes for older glioblastoma (GBM) patients ≥ 65 years of age as compared to younger patients &amp;lt; 65 years of age. The cellular mechanisms associated with this age-dependent survival difference remain elusive. Here we evaluated the overall survival of young and old immunocompetent mice with intracranial brain tumors that were depleted for specific immune cell populations. METHODS Young 6-8 weeks of age vs old 80+ weeks of age C57BL/6 mice were treated for up to 3 weeks with either IgG isotype control antibodies or with depleting antibodies against murine CD4, CD8, or NK1.1, beginning at 3 days prior to- and every 3 days post-intracranial injection of the mouse brain tumor cell lines, GL261 or CT-2A. Overall survival was compared between groups. Additionally, absolute peripheral blood mononuclear cell (PBMC) counts for CD3+ T cells, CD4+ T cells, and CD8+ T cells were analyzed between aneurysm control- and GBM-patients. RESULTS Older adult mice, but not younger mice, with either intracranial GL261 or CT-2A cell-based brain tumors have a significantly decreased overall survival when depleted for CD4+ T cells as compared to the IgG control-treated group, as well as groups depleted for CD8+ T- or NK-cells (P &amp;lt; 0.05). Coincidently, older GBM patients have fewer CD4+ T cells as compared to younger GBM patient counterparts (P &amp;lt; 0.05). CONCLUSIONS The data suggest that the levels of CD4+ T cells play more important roles in the survival of old subjects with GBM than in the younger subjects. A mechanistic understanding for this CD4+ T cell-dependent survival benefit is ongoing.
DDDR-11. TREATING DIPG WITH A MITOCHONDRIALLY TARGETED PLATINUM(IV)-BASED PRODRUG
Authors: Sudhir Raghavan, Martyn Sharpe, David Baskin
Journal: Neuro-Oncology (2022)

Abstract Diffuse intrinsic pontine glioma (DIPG) is a universally fatal childhood cancer of the brain with 5-year survival rates of &amp;lt; 2%. Despite the introduction of conventional chemotherapy and radiotherapy, improvements in survival have been marginal and long-term survivorship is rare. We previously developed MP-Pt(IV), monoamine oxidase B (MAOB) sensitive, mitochondrial targeting platinum-(IV) based prodrug derived from the chemotherapeutic cisplatin. MP-Pt(IV) is well tolerated and is highly effective in a mice xenograft GBM brain tumour model. Unlike in GBM, the expression levels of MAOB in DIPG are unknown. We tested MP-Pt(IV) against DIPG to test whether DIPG exhibit a similar sensitivity to mitochondrially targeted Pt(IV)-based prodrugs. METHODS In-vitro cell growth inhibition studies were conducted on DIPG cells using MP-Pt(IV). Labeling studies were carried out with MitoSox, MitoTracker, and H2DCFAM. Oxygen consumption studies were performed to show mitochondrial targeting. Clonogenic survival assay and scratch assay were performed. RESULTS MP-Pt(IV) shows potent growth inhibition of DIPG in cell culture studies. Mechanistic studies indicate mitochondrial targeting of the prodrug. Significant increases in cellular super-oxide and hydrogen peroxide levels are observed upon MP-Pt(IV) treatment. Oxygen consumption studies confirm mitochondrial targeting of MP-Pt(IV). MP-Pt(IV) strongly inhibits clonogenic survival and cell migration in treated cells. CONCLUSIONS We demonstrate that MP-Pt(IV) is highly effective in DIPG in vitro and is a good candidate for testing in a DIPG xenograft animal model and further development.
EPID-07. A SYSTEMIC REVIEW OF PHASE II SINGLE-ARM TWO-STAGE DESIGNS IN GLIOBLASTOMA
Authors: Wonsuk Yoo, Shwetal Mehta, Nader Sanai
Journal: Neuro-Oncology (2022)

Abstract Even though two-stage designs have been popularly in oncology Phase 2 single-arm trials during last decade, none, to our knowledge, has examined the usage for published articles that had applied the two-stage designs in Phase 2 single-arm trials in glioblastoma. It might be valuable to perform a comprehensive review on the phase 2 single-arm two-stage trials in glioblastoma for examination of appropriate application on the two-stage designs. Systematic review has been performed under the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA)-statement. The search was performed using following key words for the literature search as index terms or free-text words: “phase II trials”, “glioblastoma”, and “two-stage design”. After identifying 81 articles based on online search, we had 32 studies included in review due to exclusion of 49 articles such as duplicates (n = 10), randomized trials (n = 7), single-stage designs (n = 5), and insufficient information (n = 27). We extracted general and two-stage design information (tumor type and setting, drugs, error types, response rates, primary endpoint, two-stage sample size data, study termination status etc). Almost 50% of single-arm two-stage studies failed to provide key information related to study designs and sample size calculation, even wrong power analysis and interpretation. Response rate and progression-free survival are used as popular surrogate endpoints for overall survival. It is time to evaluate other potential endpoints like post-progress survival and hazard ratio, and usefulness of co-primary endpoint. Studies less than 10% provided the historical data source. Investigators should keep transparency of the trials by fully providing and citing historical data source and do conservative choice for historical rates. Meta-analysis can be a good option to accurately estimate the historical control. The appropriate selection on primary endpoint, historical control data, incorporation of adaptive designs, right application of two-stage designs might help overcoming the challenges on glioblastoma therapeutic trials.
IMMU-35. TREM2 RESTRAINS ANTI-TUMOR CELL ACTIVITY OF MYELOID CELLS IN GLIOBLASTOMA
Authors: Rui Sun, Saad Khan, Jingqin Luo, Colin McCornack, Yun Chen, Haowu Jiang, Diane D Mao, Alicia Yang, Qin Liu, Allegra Petti, David Holtzman, Albert Kim
Journal: Neuro-Oncology (2022)

Abstract Tumor-associated myeloid cell populations occupy a major part of the glioblastoma (GBM) tumor microenvironment (TME). The prevailing view is that myeloid cells in the TME are immunosuppressive and promote GBM tumor progression. However, myeloid cells have the functional plasticity to either restrict or support tumor cell growth. TREM2 has been shown to alter the myeloid cell landscape in cancers arising in the body and plays important roles in brain microglial function in neurodegenerative diseases. But the role of TREM2 in the GBM TME and specifically in myeloid cell function has not been examined. Here we found that TREM2 is highly expressed in myeloid subsets, including macrophages and microglia in human and mouse GBM tumors, and that high TREM2 expression is associated with poor prognosis in GBM patients. TREM2 loss of function in human macrophages and mouse myeloid cells increased tumoricidal capacity in vitro using patient-derived glioblastoma stem cells and mouse glioblastoma cells. Accordingly, we found TREM2 in myeloid cells restricts proinflammatory polarization in both LPS-induced innate and IFNγ-induced adaptive immunity in vitro, mainly through the inhibition of NFκB and MAPK p38 signaling pathways. Orthotopic injection of mouse glioblastoma cells into TREM2 knockout mice increased animal survival compared to littermate wildtype mice. In addition, co-implantation of TREM2 knockdown macrophages or microglia with mouse glioblastoma cells in brains of immunocompetent mice increased animal survival compared to co-implantation of control myeloid cells or injection of tumor cells alone, suggesting an important role for TREM2 in myeloid cells in GBM growth in vivo. Together, these data indicate that TREM2 operates by restricting the anti-tumor and proinflammatory function of myeloid cells in GBM and that inhibition of the TREM2 pathway may represent a potential therapeutic strategy for these patients.
BIOM-44. MAGNETIC RESONANCE IMAGING MAPPING OF BRAIN TUMOR BURDEN TO EVALUATE RESPONSE TO PULSED LOW-DOSE-RATE RADIOTHERAPY FOLLOWING RESECTION OF GLIOBLASTOMA MULTIFORME: A 4-PATIENT CASE SERIES
Authors: Ryan Amidon, Melissa Prah, Michael Straza, Fernando Santos-Pinheiro, Joseph Bovi, Christopher Schultz, Kathleen Schmainda
Journal: Neuro-Oncology (2022)

Abstract BACKGROUND Pulsed low-dose-rate radiotherapy (pLDR) is an accepted reirradiation technique for recurrent glioma, but its upfront use, concurrent with temozolomide (TMZ) following resection of high-grade glioma is currently under investigation. Evaluating the response to upfront radiation can be challenging and there is limited data on expected rates of pseudoprogression with pLDR. Standard magnetic resonance imaging (MRI) has limitations in differentiating pseudoprogression from tumor progression, sometimes necessitating surgery for pathologic confirmation. Advanced MRI can be used to create fractional tumor burden (FTB) maps that spatially distinguish active tumor from treatment-related effect (pseudoprogression), perhaps providing a more reliable imaging biomarker in the absence of additional surgery. METHODS We performed a retrospective chart review to report the responses of four patients with glioblastoma to upfront pLDR and TMZ following resection. Each patient received advanced surveillance MRI and redo surgery. Tumor pathology included IDH-wild type (n = 4) and O6-methylguanine-DNA methyltransferase (MGMT) methylated (n = 1) tumors. RESULTS The median age of patients was 57.5 years (range 55-60 years) and all were male. One patient experienced mortality and another was transitioned to hospice. In all four cases, there were concerns of tumor progression in postcontrast MRI. Pathologic diagnosis revealed either treatment effect (n = 2) or tumor (n = 2). FTB maps were predominantly indicative of lesion volumes being comprised of treatment effect (n = 3) and tumor (n = 1). From the three FTB maps in the former category, the median fraction of the enhancing tumor volume comprised of vascular tumor was 6.4% (range 1.8-6.8%). CONCLUSION This case series provides insight into response to upfront pLDR and TMZ following resection of glioblastoma and demonstrates the capacity for FTB mapping to spatially distinguish tumor progression from treatment effect in this patient population.
IMMU-08. RAGE ABLATION ATTENUATES GLIOMA PROGRESSION AND ENHANCES TUMOR IMMUNE RESPONSES BY SUPPRESSING GALECTIN-3 EXPRESSION
Authors: Mojtaba Dayyani, Ian Zhang, Shunan Liu, Leying Zhang, Rongrui Liang, Qinxiao Fang, Jie Zhao, Lyuzhi Ren, Eric Medina, Aleksandr Filippov, Kimberley-Jane Bonjoc, Ammar Chaudhry, Andrea Bild, Behnam Badie
Journal: Neuro-Oncology (2022)

Abstract INTRODUCTION Malignant gliomas consist of heterogenous cellular components that have adopted multiple overlapping escape mechanisms that overcome both targeted and immune-based therapies. The receptor for advanced glycation end products (RAGE) is a member of the immunoglobulin superfamily that is activated by diverse proinflammatory ligands present in the tumor microenvironment (TME). Activation of RAGE by its ligands stimulates multiple signaling pathways that are important in tumor growth, invasion, and immune escape. OBJECTIVE We aimed to demonstrate that blockade of RAGE expression may tackle resistance pathways by inhibiting GBM progression, invasion, and immune evasion. METHODS We evaluated genetic ablation of RAGE on the tumorigenicity of two syngeneic murine glioma models. RAGE expression was inhibited in the GL261 and K-Luc gliomas by shRNA and CRSPR/Cas9 techniques prior to intracranial implantation. Tumor growth, invasion, and inflammatory responses were examined by immunohistochemistry, qPCR, ELISA, western blotting, NanoString, flow cytometry, and in vivo survival analysis. RESULTS Intracellular RAGE ablation abrogated glioma growth and invasion by suppressing AKT and ERK1/2 activities and by downregulating MMP9 expression. Interestingly, RAGE inhibition also enhanced tumor inflammatory responses by downregulating the expression of galectin-3, rendered the immunotherapy resistant K-Luc gliomas responsive to immune checkpoint blockade therapy, and significantly increased survival. CONCLUSION This study is the first to link RAGE expression with galactin-3 as an immune modulator in glioblastoma and revealed that the effect of glioma RAGE expression on TME was mediated through downregulation of Gal-3 and subsequent polarization of Tumor-associated macrophages. The therapeutic significance of RAGE downregulation was demonstrated by sensitizing a highly invasive and immune-resistant glioma model to immune checkpoint blockade and strongly supports the development of RAGE ablation as a complementary treatment strategy for malignant gliomas.
DDDR-14. YAP/TAZ TRANSCRIPTIONAL CO-ACTIVATORS DRIVE NEURO-GLIAL STEM/PROGENITOR CELL IDENTITY IN HIGH GRADE GLIOMAS
Authors: Renee Read, Se-Yeong Oh, Krishanthan Vigneswaran, Nathaniel Boyd, Elizabeth Young, William Read, Jeffrey Olson
Journal: Neuro-Oncology (2022)

Abstract High-grade gliomas (HGGs), neoplasms derived from neuro-glial stem/progenitor cells, are the most common and lethal malignant primary brain tumors diagnosed in adults and children, with a median survival time of 14 months with current treatments. HGG tumorigenicity is often driven by genetic aberrations in receptor tyrosine kinases (RTKs), such as EGFR, and the Pi-3 kinase (PI3K) signaling pathway. Using Drosophila, mouse, and human HGG model systems of RTK-PI3K mutant HGGs, we identified the YAP and TAZ transcription co-activators, which regulate gene expression via TEAD co-factors, as key drivers of HGG tumorigenicity downstream of oncogenic RTK signaling. YAP and TAZ are highly expressed in RTK-mutant human HGG cells, and regulate TEAD-mediated transcription of several transcription factors, neurodevelopmental genes, and receptors, including the EGFR RTK, that together create a feedforward loop with RTKs to maintain a radial-glia-like stem/progenitor cell fate in HGG cells. Inhibition of YAP and TAZ in self-renewing stem-cell-like RTK mutant HGG cells can inhibit proliferation, block stem/progenitor cell fate, and elicit apoptosis. In particular, the benzoporphyrin derivative verteporfin, a disruptor of YAP/TAZ-TEAD mediated transcription, specifically induced apoptosis of cultured patient-derived HGG cells, suppressed expression of YAP/TAZ transcriptional targets, including RTKs, and conferred significant survival benefit in an orthotopic xenograft HGG model. Our efforts led us to initiate phase 0 and phase 1/2 clinical trials of Visudyne, an FDA-approved liposomal formulation of verteporfin, in which we have verified verteporfin uptake into tumor cells and are now testing the therapeutic efficacy of verteporfin in human patients. Finally, we have examined mechanisms of response and resistance to verteporfin, and we have evidence that stem-like HGG cells can escape the effects of YAP/TAZ inhibition by recapitulating neuro-glial developmental cell fate transitions. Together, our data indicate that targeting YAP/TAZ functionality is a promising therapeutic approach for HGG.
IMMU-34. NL-201, A DE NOVO ENGINEERED IL2 MIMETIC, SYNERGIZES WITH RADIOTHERAPY TO GENERATE POTENT ANTITUMOR ACTIVITY IN PRECLINICAL GLIOBLASTOMA MODELS
Authors: Kristin Huntoon, DaeYong Lee, Yifei Lu, Thomas Gallup, Wen Jiang, Betty Kim
Journal: Neuro-Oncology (2022)

Abstract Combining radiotherapy (RT), a standard of care treatment for many cancer types, with immunotherapeutic agents has been gaining interest due to improved efficacy. One such approach is RT in combination with high-dose recombinant interleukin 2 (IL-2), which elicits anti-tumor immune responses by stimulating T-cell and NK cell populations. Although effective for some patients, the overall clinical benefit of recombinant IL-2 is limited by toxicity at high doses and the expansion of regulatory T cells (Tregs) at low doses, effects thought to be mediated by preferential binding to IL2Rα (i.e. CD25). In this study we examined RT in combination with NL-201, a highly potent and stable CD25-independent IL-2/IL-15 agonist with enhanced affinity for the IL-2Rβγ heterodimeric receptor. Single-agent NL-201 was well tolerated in mice, yielded tumoricidal activity, expanded peripheral T cells, and enhanced the infiltration of effector T cells and dendritic cells (DCs) into murine glioblastoma (GL261 and SB28). In combination with RT, NL-201 enhanced activation of the cytosolic DNA sensor cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway, resulting in increased type I interferon (IFN) production in DCs and, consequently, greater tumor infiltration by T cells and more efficient priming of antigen-specific T cells by professional antigen presenting cells (APCs). The immune stimulatory mechanisms triggered by the NL-201 and RT combination resulted in superior tumor growth inhibition. We demonstrated that the CD25-independent IL-2 and IL-15 receptor agonist, NL-201, in combination with RT is well-tolerated and elicits robust anti-tumor activity through both innate and adaptive responses, including in checkpoint resistant tumors. Furthermore, we identify a unique mechanism in which NL-201 synergizes with RT. Taken together, the results provided herein support further preclinical and clinical investigation of this novel combination regimen.
BIOM-40. COMPARATIVE STUDY OF INFLAMMATORY MARKERS IN THE CEREBROSPINAL FLUID OF PATIENTS WITH GLIOMA AND CENTRAL NERVOUS SYSTEM MALIGNANT LYMPHOMA
Authors: Takashi Sasayama, Kazuhiro Tanaka, Hiroaki Nagashima, Yuichi Fujita, Hirofumi Iwahashi, Yoshinori Kodama, Masamitsu Nishihara
Journal: Neuro-Oncology (2022)

Abstract INTRODUCTION Cytokines in the cerebrospinal fluid (CSF) are useful as markers for primary central nervous system malignant lymphoma (PCBSL). However, there are few reports of CSF markers in glioma. We analyzed and examined glioma and PCNSL CSF inflammation-related mediators. MATERIALS AND METHODS The patients with glioma and PCNSL who were operated on at Kobe University between 2006 and 2017 and whose histology was diagnosed, and whose CSF was stored at -80 °C before treatment. Using Bio-Plex Pro Human Inflammation Assays (Bio-Rad Laboratories, Inc.), 37 types of inflammation-related molecules such as TNF superfamilies, interferonss, and Interleukines were measured and compared with glioma and PCNSL. RESULTS The subjects were 53 glioma patients and 24 PCNSL patients. There were 22 types of significant differences between glioma and PCNSL, 18 with high PCNSL and 4 with high glioma. In addition to IL-10, which has been reported so far, the significant higher concentrations in PCNSL was found in Osteopontin, TNFSF8, TNFSF12, TNFSF13, TNFSF13B, TNFSF14, sTNF-R1, sTNF-R2, IL-6Ra, IL-8, IL-12(p40), IL-20, IL-27, sCD163, MMP2, MMP3, CHI3L1. On the other hand, IL-2, Il-12(p70), IL-22, and MMP-1 levels were significant higher in CSF in glioma. Although CD163 is an important molecule as a marker for M2 macrophages, immunostaining of tissues showed no significant difference in infiltration between Glioblastoma and PCNSL. This suggests that M2 macrophages infiltrating PCNSL and Glioblastoma have different activation states. CONCLUSION PCNSL had higher levels of inflammatory mediators such as TNF-related molecules. PCNSL was significantly higher in sCD163 than in glioblastoma, suggesting different activation of intratumoral M2 macrophages.